數據寫入文件的幾種方法速度比較

import java.io.File;
import java.io.FileOutputStream;
import java.io.*;
public class FileTest {
public FileTest() {
}
public static void main(String[] args) {
FileOutputStream out = null;
FileOutputStream outSTr = null;
BufferedOutputStream Buff=null;
FileWriter fw = null;
PrintWriter pw = null;
PrintWriter pw1 = null;
int count=100000;//寫文件行數
try {
out = new FileOutputStream(new File(“d:/add.txt”));
long begin = System.currentTimeMillis();
for (int i = 0; i < count; i++) {
out.write(“測試java 文件操作\r\n”.getBytes());
}
out.close();
long end = System.currentTimeMillis();
System.out.println(“FileOutputStream執行耗時:” + (end - begin) + ” 豪秒”);
outSTr = new FileOutputStream(new File(“d:/add0.txt”));
Buff=new BufferedOutputStream(outSTr);
long begin0 = System.currentTimeMillis();
for (int i = 0; i < count; i++) {
Buff.write(“測試java 文件操作\r\n”.getBytes());
}
Buff.flush();
Buff.close();
long end0 = System.currentTimeMillis();
System.out.println(“BufferedOutputStream執行耗時:” + (end0 - begin0) + ” 豪秒”);
fw = new FileWriter(“d:/add1.txt”);
long begin3 = System.currentTimeMillis();
for (int i = 0; i < count; i++) {
fw.write(“測試java 文件操作\r\n”);
}
fw.close();
long end3 = System.currentTimeMillis();
System.out.println(“FileWriter執行耗時:” + (end3 - begin3) + ” 豪秒”);
pw = new PrintWriter(“d:/add2.txt”);
long begin4= System.currentTimeMillis();
for (int i = 0; i < count; i++) {
pw.write(“測試java 文件操作\r\n”);
}
pw.close();
long end4 = System.currentTimeMillis();
System.out.println(“PrintWriter執行耗時:” + (end4 - begin4) + ” 豪秒”);
pw1 = new PrintWriter(new FileWriter(“d:/add3.txt”));
long begin5= System.currentTimeMillis();
for (int i = 0; i < count; i++) {
pw1.write(“測試java 文件操作\r\n”);
}
pw1.close();
long end5 = System.currentTimeMillis();
System.out.println(“PrintWriter FileWriter執行耗時:” + (end5 - begin5) + ” 豪秒”);
} catch (Exception e) {
e.printStackTrace();
}
finally {
try {
fw.close();
Buff.close();
outSTr.close();
out.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
}

這是count=100000的結果，字節流是最慢的，緩衝Buffer速度比較穩定，PrintWriter直接加載文件比先用FileWriter加載然後再用PrintWriter輸出速度快。

PrintWriter以字符爲單位，支持漢字，
OutputStreamWriter以字節爲單位，不支持漢字

寫文件最佳組合
PrintWriter out = new PrintWriter(
new BufferedWriter(
new FileWriter(filename)));
PrintWriter 提供println()方法可以寫不同平臺的換行符
BufferedWriter 可以任意設定緩衝大小。提供緩衝，用以加速
FileWriter 用於寫文件